Comprising the entire 18th floor and half of the 19th floor, the units can be combined to create a single home of about 10,000 square feet

A week after its 24th floor penthouse went on the market for $70 million, or nearly $20 million more than it sold for less than two years ago, three other apartments at Manhattan’s Walker Tower are listing together for a total of $60 million.

Comprising the entire 18th floor and half of the 19th floor, the units can be combined to create a single home of about 10,000 square feet, with two interior staircases and four terraces, said listing agent Michael Graves of Douglas Elliman Real Estate, who shares the listing with Elliman colleague Vickey Barron.

The units are owned by two of the building’s developers, Elliott Joseph and Kevin Maloney of Property Markets Group. Along with JDS Development Group, Property Markets Group converted the Art Deco office building into a condominium with about 50 units. Condo sales started in 2012. Though the Chelsea building sold out in November, the sponsors each kept several apartments, said Mr. Joseph.

Units 18A and 18C, which are owned by Mr. Joseph, were already on the market for a total of $44.5 million. They are now being offered as a combination with unit 18D, which is owned by Mr. Maloney and is also separately on the market for $15.65 million. It would be up to the purchaser to combine the units, Mr. Graves said.

As the 24th floor penthouse is around 6,000 square feet, Mr. Graves said the combination of the three units is “asking half as much” on a per-square-foot basis.